Cold Spell Discussion

[Methuselah]

Here y'all go...Previous:

[Duncan McAlister]

How come this seems to have been such a major event for many people when Sunday/Monday was mainly sleet and rain, despite milder uppers now?

Edited January 13, 2010 by Duncan McAlister

[Thundery wintry showers]

The Sunday/Monday event was heavily modified by the warming effects of the long air track over the warm North Sea. An ENE'ly or NE'ly is great news for cold/snow lovers if the airmass is unstable and cold, bringing repeated heavy snowfalls to eastern areas (as we saw during 17/18 December and again during the first nine days of January). But as soon as the word "marginal" creeps in, the long track over the sea tends to result in sleet or rain for many.

Notably, the warming effects of the North Sea had largely tapered off by the time the airmass reached south-west England and that's why many parts of that region saw lying snow from the event.

This event has an input of continental air with a much shorter sea track, and therefore, although the uppers are warmer, there is less airmass modification and so temperatures are generally lower.

[Eugene]

Well here in warwickshire it was snow sunday night, got a slight topping from it but nothing like today of course, it seems this caught alot of people out saying how could it snow when we had a slow thaw and temps around 1C by day, seemed pretty obvious to me it would snow today though i didnt expect this much, it wasnt like we were mild anyway, in the midlands alot of places were 1C in previous day and yesterday we picked up cold dew points from the continent and a pool of< -5C 850 hPa uppers.

http://www.wetterzentrale.de/pics/Rtavn001.png - Great chart for snow with LP undercutting HP to our northeast.

Not many would forecast snow in the south today, the usual uppers too warm for that argument would come out :lol:

[Andy Bown]

The current mean for Warminster this month is -2.75c!!

Average max = 0.45c (including 4 ice days)

Average min = -3.20c

What means do other members have for the moth so far?

[Eugene]

What is amazing too is the mild spell for the weekend is being downgraded all the time, well for the midlands northwards/eastwards with the mild dew points not making it this far west, it could be a quite chilly strong southerly wind now for these areas, that high to our east is squeezing all the mild air out of the system, i just don't see the atlantic being strong enough to blast away a renewed HP build early next week, the jet seems to be weakening by the run.

There will be a thaw though for the midlands at the weekend, which is good to wash away the snow that will melt on friday.

Edited January 13, 2010 by Eugene

[Bobby]

Got ~7 inches of snow from this snow event. ~10 inches total now, I think that's the deepest I can remember since 1996.

[Timmytour]

Just speaking to a colleague in Washington DC area. I'm always amazed at how similar the weather often is both here and there. Like us they've been going through a cold spell. But he's telling me that temps are slowly climbing above freezing and are expected to get as high as the mid 50s F by the end of next week. I don't think this bodes well for us :unsure:

[Pixel]

Any chance someone can tell whether it's rain, sleet or snow falling from this little development over France.. a link to a site with details would be greatly appreciated

http://www.meteox.com/h.aspx?r=&jaar=-3&soort=satradar

Cheers

[hugogo]

Any chance someone can tell whether it's rain, sleet or snow falling from this little development over France.. a link to a site with details would be greatly appreciated

http://www.meteox.co...&soort=satradar

Cheers

Hey,

I don't know if any of you know this link: http://www.meteociel.com/

Excellent website, you've got observations for every country including Britain here:

http://www.meteociel.com/obs/pays.php?pays=United+Kingdom&jour=13&mois=1&annee=2010&heure=15&ok=OK

You've got the model forecasts aswell [uKMO, CEP, GFS, NOGAPS, GEM, JMA, WRF...], and of course a decent observation map for France and surrounding countries.

Have fun!

Hugo.

[Osbourne One-Nil]

And if you live further north than Manchester, or you want the maps in English, you could try a site called Netweather!

EDIT - ah - just noticed you were specifically after France. Sorry!

Edited January 13, 2010 by Osbourne One-Nil

[Iceni]

Any chance someone can tell whether it's rain, sleet or snow falling from this little development over France.. a link to a site with details would be greatly appreciated

http://www.meteox.co...&soort=satradar

Cheers

From the NW radar Euro view, it's rain.

[Pixel]

From the NW radar Euro view, it's rain.

Iceni, Hugago and Oon thank you all for the info - brilliant forum this :lol:

Looks like it's breaking up and losing intensity now, tho there's something larger behind.. I'm no model analytic but I thought fog formed in still air (the forecast for my area) which is why I was following this - secretly looking for surprises! I guess upper air can be quite fast moving yet at ground level it's barely noticed.

[Supercell]

The current mean for Warminster this month is -2.75c!!

Average max = 0.45c (including 4 ice days)

Average min = -3.20c

What means do other members have for the moth so far?

Mean Max: 1.4C

Mean Min: -3.5C

Mean Temp: -1.0C

[Thunder Snow]

W might not have to wait long for the next cold spell.

[damianslaw]

What is amazing too is the mild spell for the weekend is being downgraded all the time, well for the midlands northwards/eastwards with the mild dew points not making it this far west, it could be a quite chilly strong southerly wind now for these areas, that high to our east is squeezing all the mild air out of the system, i just don't see the atlantic being strong enough to blast away a renewed HP build early next week, the jet seems to be weakening by the run.

There will be a thaw though for the midlands at the weekend, which is good to wash away the snow that will melt on friday.

I agree the block to the east is very strong and showing signs of ridging westwards early next week, however, we have to watch what is happening to the north of us, alot of energy is suddenly being transferred into the northern arm of the jet, ideally we want more energy to go into the southern arm, otherwise we are very likely to see shortwaves topple into the north west of the high sending it southwards, which means we will quickly loose the easterly feed and convert it to a mild atlantic regime, still there is chance that we see enough of a split jet to maintain the high in a more favourable position, i.e. the jet is sent much further northwards, all eyes on the jetstream at the moment I feel, on a positive the atlantic does look fairly weak and if we do see an atlantic onslaught next week, it could easily be a very temporary affair.

[Thunder Snow]

So how are things looking next week at the moment, any good for widspread snow lol.

[Liam J]

well this morning i woke to the most snow i have had for quite a few years, only 2 inch which many will laugh at, but im only 70m asl, and while many forecasts said rain we have snow accumulating... and i have been told thats its settled on boats in the village harbour.

Edited January 14, 2010 by james12

[Osbourne One-Nil]

We had half an inch overnight which has fallen on top of wet, unsalted and in places still snow covered roads, making today's drive in to work one of the worst yet. I was ok, but Transit man driving the other way clearly thought he was driving a range rover.

[chionomaniac]

Thanks Tammy. Perhaps I should have said "all winter and every winter" for the less perceptive amongst you.

Mr OON, I am sure that you have a far greater understanding of the models than a lot of people here, so rather than commenting on other peoples contributions, why not comment positively on what your thoughts are of the current model output. I, and I am sure many others on here would welcome that.

Here are my thoughts. There are certainly good reasons why both the troughing around Greenland could be greater or less than the models are showing and I have covered these in the strat thread. It may appear that the large Siberian high is an immoveable object but if the blocking forecasts are anything to go by then in 14 days time we may see a trough where currently we see that great big high and a ridge over Greenland.

c

[Osbourne One-Nil]

Mr OON, I am sure that you have a far greater understanding of the models than a lot of people here, so rather than commenting on other peoples contributions, why not comment positively on what your thoughts are of the current model output. I, and I am sure many others on here would welcome that.

I don't know anything about the models. That's why I come here...to learn about them. It is a perfectly valid course of action.

[chionomaniac]

I don't know anything about the models. That's why I come here...to learn about them. It is a perfectly valid course of action.

After over 15000 posts, 6 years on here and more on slow watch, I reckon that you may have learnt a little bit by now, OON!

Edited January 14, 2010 by chionomaniac

[Osbourne One-Nil]

Trust me. I stole the A level biology paper before I sat the mock exam, and I still failed.

[Thunder Snow]

I still have light snow, had this since last night nearly 2cm

[ANYWEATHER]

Tomaz S on the Radio 4 said that a return to colder conditions next week and he sounded pretty resolute in his manner, thats after a very mixed weekend ...Oh well!